Polyester fabrics are ideal in active and sportswear mainly due to their high breathability which ensures the comfort of the wearer during heavy workout sessions. However, these fabrics are being greatly rejected from these communities irrespective of the comforting touch and feel, because of the strong malodor they produce upon standing even after a strong detergent wash. This malodor development is found to be related to the special surface make up of polyester fabrics.
A preliminary investigation on the structure reveals that polyester yarns have grooves on their surfaces as an inherent structural property unlike the case of nylon and cotton where the surface appears to be smoother with no grooves. The presence of grooves enhances wicking and drying properties of polyester fabrics which make them better candidates in sportswear surpassing common active wear yarns. Quick passage of water through polyester fabrics is ensured by its fibers being hydrophobic and hence not getting wet much. Presence of grooves on the fiber surface further enhances the breathability of polyester fabrics by empowering the capillary channel system through which water flows in the fabric by the capillary action.
Even though grooved surface is very advantageous in polyester, in turn it is also the biggest weakness of it. This is because, when the surface is filled with grooves, it provides a versatile breeding ground for the skin flora. Bacteria associated with skin flora get readily attached irreversibly to these hydrophobic surfaces through hydrophobic interactions. Once attached, they colonize forming a biofilm on the attached surface. In the process of their multiplication and growth, odorless apocrine secretions (rich in glutamine conjugates) are degraded to produce odorous compounds like short chain fatty acids (C6-C10): like pelargonic (C9) capric acid (C10) and 3-methyl-2-hexenoic acid (C7) being the most common. The formation of these odorous compounds make the polyester garments stink even after continuous laundering.
Human axilla is dominated by four major classes of bacteria which include staphylococci, aerobic coryneforms, propionibacteria and micrococci species that are responsible for the aforementioned biotransformation of odorless organic precursors to their respective odoriferous compounds. Polyester fabrics get susceptible to malodor development when these microbes in skin flora migrate onto the fabric and start degrading the sweat compounds adsorbed into fabrics during workouts. Grooves on polyester which are meant to be the elements for increasing drying and wicking properties of fabrics for the breeding ground for these microbes.
Therefore, development of odor free polyester fabric is marked as a compromise between maintaining the breathability of polyester while preventing the bacterial degradation of sweat compounds on them. There are a number of commercial products with embedded organic and inorganic bactericidal agents and nano silver, nano titania based surface finishes. See Shahidi, S., Wiener, J. (2012) Antibacteral Agents in Textile Industry, V. Bobbarala (Ed.), Antimicrobial Agents ISBN: 978-953-51-0723-1, InTech, DOI: 10.5772/46246, U.S. Pat. No. 7,629,000 B2, Maleknia, L., et al., Antibacterial properties of Nanosized Silver Colloidal Solution on Wool Fabric, Asian journal of Chemistry, 2010, 22(8), 5925-5929.
Photocatalysis by Calcium Hydroxyapatite Modified with Ti (IV), Masato Wakamura, Fujitsu Sci. Tech. J., 41, 2, p. 181-190, July 2005 discloses the photocatalysis activity of Hydroxyapatite Modified with Ti (IV). In the document, the author discloses that Ti (IV) modified Hydroxyapatite shows bactericidal activity.
However, all these finishes are antibacterial finishes. Even though they prevent the odor development of polyester, there's a risk of death of beneficial skin flora during their mechanism of action.
There is a need to develop modified fabrics, which while tackling the issue of odor development, would also not cause any detrimental effect on the skin flora whereby none of the beneficial microorganisms would be killed or their growth retarded as a result of such modification.
Thus, while in the prior art, agents used for coating textiles/fabrics are anti-bacterial agents which kill bacteria, the agent used for treating textile/fabric in the present invention functions by modifying the surface of the fabric/textile and acts as a bacterio-repulsive agent, thereby not causing any harm to the skin flora. These aspects are not known in the prior art.